Field
Exemplary embodiments of the present invention relate to a position controller, a method of controlling a position, and an apparatus including the position controller.
Discussion of the Background
Display apparatuses are used to provide visual information such as images or is pictures to users. Such display apparatuses are manufactured in various shapes.
Particularly, organic light-emitting display apparatuses are light-emitting displays for emitting light by electrically exciting organic compounds. These displays are attracting attention as next generation displays, because they are driven at a low voltage, are easily manufactured thin, and overcome the limitations of liquid crystal displays to provide wide optical viewing angles and rapid response speeds.
The goals in manufacturing display apparatuses are high precision, high integration, and large size. Therefore, accurately positioning an apparatus for processing/observing workpieces is important. For this purpose, deposition systems for display apparatuses includes position controllers for checking the current position of workpieces or processing/observing apparatus and accurately moving the workpieces or processing/observing apparatus to target positions.
Generally, position controllers include interferometers using lasers and mirrors. For example, the mirror may be disposed on a stage, on which the workpiece is placed, and the interferometer may be disposed outside to continuously observe the position of the stage. Alternatively, the interferometer may be disposed on the stage and the mirror is disposed outside to continuously observe a position of the stage.
However, as the enlargement of the stage have been promoted, it became more difficult to manufacture larger mirrors with high precision, increasing the manufacturing cost. To overcome such limitations, research has been performed to replace large minors with smaller minors combined. However, a new problem arose as it became necessary to precisely arrange a plurality of mirrors. Additionally, since an interferometer is affected by peripheral temperature and humidity, additional devices for maintaining temperature and humidity uniformly are utilized.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.